Fluid pressure motor



March 27, 1956 HAMNER FLUID PRESSURE MOTOR Filed A ril 7. 1953 2 Sheets-Sheet 1 Q N Q March 27, 1956 AMNER 2,739,573

FLUID PRESSURE MOTOR Filed April 7, 1953 2 Sheets-Sheet 2 INVENTOR Iewz}; 133277272292:

E1EE. 115.5... Eli-51A- United ,StfllICS Fatent G FLUID PRESSURE MOTOR Lewis T. Hamner, Petersburg, Va., assignor to Vacuum Motor Corporation, Petershurg, Va., a corporation of Virginia Application April 7, 1953, Serial No. 347,254 13 (Ilaims. (Cl. 121-157) This invention relates generally to fiuid pressure motors and primarily seeks to provide a novel motor structure of this character having a power applying or actuator piston which is reciprocated by air at atmospheric pressure and under vacuum control.

An object of the invention is to provide a motor of the character stated wherein the reciprocation of the actuator piston is brought about by alternately elfecting communication at one side of the piston with a vacuum source while efiecting communication at the other side of said piston with air at atmospheric pressure.

Another object of the invention is to provide a motor of the character stated wherein the controlling of the vacuum and atmospheric air communication is effected by operation of a reciprocable valve piston.

Another object of the invention is to provide a motor of the character stated wherein the reciprocation of the valve piston is effected by pressure operated control pistons under control of valve means actuated by the reciprocating actuator piston.

Another object of the invention is to provide a motor of the character stated wherein the control pistons are atmospheric air operated under vacuum control through the actuator piston actuated valve means.

Another object of the invention is to provide a motor of the character stated wherein the valve piston, the control piston and the valve means have connection with a common vacuum source.

Another object of the invention is to provide a motor of the character stated wherein means is provided for affording vacuum communication of like value to the control piston and the two valve means, and between each valve means and a cooperating control piston at an individually variable value.

Another object of the invention is to provide a motor of the character stated wherein there are included novel variable air venting means effective to control the rate of movement of the actuator piston on one or both stroke movements thereof.

.Another object of the invention is to provide a motor of the character stated wherein the valve means associated with each control piston opens vacuum communication only momentarily at each stroke change of the actuator piston, and wherein a duct effecting each such communication has an adjustable valve therein for controlling a vacuum value always less than that of the common vacuum source.

With the above and other objects in view that will hereinafter appear, the nature of the invention will be more clearly understood by reference to the following detailed description, the appended claims with the several views illustrated in the accompanying drawing.

In the drawings:

Figures 1 and 1a when joined at the line AA, B-B together comprise a somewhat diagrammatic side elevation and part vertical longitudinal section illustrating one adaptation of the invention arranged for continuous reciprocation of the actuator piston so long as the vacuum source is in eiiective communication.

2,739,523: Patented Mar. 27, 1956 Figure 2 is an enlarged fragmentary vertical cross section taken on the line 2'-2 on Figure 1.

Figure 3 is an enlarged fragmentary vertical cross section taken on the line 33 on Figure 1.

Figure 4 is an enlarged vertical longitudinal section through one of the variable vacuum control valves.

Figure 5 is an enlarged vertical cross section through one of the variable air vent valves.

In the somewhat diagrammatic illustration of the invention in Figures 1 and la wherein an example arrangement of the invention is shown, there are included a vacuum source generally designated A, an actuator or power cylinder generally designated B, a control cylinder generally designated C, a left shift control valve generally designated D, a cooperating left shift control actuator cylinder generally designated E, a right shift control valve generally designated F, and a cooperating right shift control actuator cylinder generally designated'G.

The vacuum source generally designated A may take the form of a pump 5 connected with the vacuum line 6 leading directly to the control cylinder C where it connects with a port 7 disposed intermediately of the ends of said cylinder. A gage is connected in the line 6, and a vacuum value controlling valve 9 also is connected in said line, such a valve being shown in detail in Figure 4.

The control cylinder C comprises a hollow cylinder 10 having a free control valve plunger 11 reciprocable therein and equipped with spaced pistons or heads 12 within the cylinder, and a plunger 13 at each end thereof and extending through and slidable in a boss 14 in the respective end of the cylinder. An adjustable air vent generally designated 15 is disposed at each end of the cylinder 10, and avacuum and air port is disposed adjacent and in longitudinally spaced relation inwardly of each said vent, one said vacuum and air port being designated 16 and the other 17.

The power cylinder B comprises a hollow cylinder 18 having a free piston 19 reciprocable therein and equipped with plungers 20 extending endwise through and slidable in the cylinder end bosses 21. A vacuum and air port 22 is disposed at one end of the cylinder and a vacuum and air port 23 is disposed at the opposite end of said cylinder. A duct 24 connects the vacuum and air port 22 with the vacuum and air port 16 of the control cylinder lit, and a duct 25 connects the vacuum and air port 23 with the vacuum and air port 17 of said control cylinder.

It is to be understood that in practical use of the motor, the plungers 20 movable with the actuator piston 19, or one thereof, will be connected in any approved manner (not shown) to a power take-off or any device to which movement is to be applied, directly as reciprocatory movement, or in any other form through suitable movement transmitting agencies.

Each of the control valves D and F includes a casing 26 having an attached mounting flange 27 and a bore 28 in which the control plunger 29 is slidable. The bore extends through one end of the casing where the plunger has an abutment screw 30 adjustably secured therein and passed through a stop washer 31 which is engageable with the casing end to limit inward movement of the plunger in the manner clearly illustrated at the right in Figure 1. At its other end the bore terminates at a cross wall 32 which is apertured at 33 to pass a stop screw 34 which is adjustably secured on the plunger end and is engageable with the wall 32 to limit outward movement of the plunger, or movement to the left as viewed in Figure 1. A compression spring35 coiled about the screw 34 Within the bore between the wall 32 and the adjacent end of the plunger 29 constantly urges the plunger toward its out- U \vai'dly projected position illustrated at the left in Figure 1.

The valve casing 25 is equipped with an upwardly opening air vent generally designated 36. An air duct is formed in the plunger 29 and includes a horizontal elbow portion 37 and a vertical leg 38 adapted at times to communicate with the air vent 36. The plunger '29 also includes a vacuum duct in the form of a vertical elbow 38, the vertical leg of which is adapted to cornmunicate at times with the vertically opening vacuum port ll), and at such times the other horizontal leg of the elbow 39 is adapted to communicate with the horizontally opening vacuum port 41. The. port 44 is connected by a duct 42 with the vacuum source line 6, and the port 41 is connected by the duct 43 with a port 44 provided at one end of the left shift; control actuator cylinder generally designated E. Said duct 43 has an adjustable valve generally designated 45 connected therein for controlling the value of the vacuum which is to be effective in said duct.

The left shift control actuator cylinder E comprises a hollow cylinder 46 having an adjustable air vent 47 at the end thereof away from the port 44. A free piston 48 is reciprocable in the cylinder 46 and has a plunger 49 projecting therefrom through the cylinder boss 59 toward the control cylinder 10.

The other or right shift control valve F has a casing 51 like the valve D, and also a plunger 52 reciprocable therein and exactly like the plunger insaid valve D. The casing 51 has an upwardly opening vacuum port 55 which is connected by a duct 54 with the suction source line 6, and its horizontally opening vacuum port 55 isv connected by a duct 56 with the port 57 at one end of the right shift control actuator cylinder G. As in the, case of the other control valve, an adjustable valve is connected in the duct s for controlling thevalue of the vacuum to be effective in said duct.

The right shift control actuator cylinder G comprises a hollow cylinder 60. having an adjustable air vent 61 at the end thereof away from the beforernentioned port 57, and a free piston 62 is reciprccable in the cylinder and. has an attached plunger projecting through the cylinder boss 64 toward the control cylinder 10.

One of the adjustable air vents previously designated 15, 36, 47, S9 and 61 is shown in detail in Figure 5 from which it will be apparent that the same. includes av removably mounted casing 65 having acentral chamber 66 into which air enters or escapes through the ports. 67, and a seat 68 through which entering air is delivered or discharging air escapes under control of the adjustably mounted needle valve 69.

One of the vacuum value controlling valves generally designated 9, 45 or 58 is shown in detail in Figure 4 from which it will beapparent that the same includes a removably mounted casing 70 having a chamber 71 into which air enters through ports 72. The air entering the ports 72 can be drawninto the respective vacuum lines or ducts through the end seat 73 under control of the valve 74 which is yieldably seated by the compression spring 75 interposed between the adjustable abutment 76 and the opposing end of the casing 70. It will be apparent that by adjusting the abutment 76 to vary. the compression of the spring 75; the resistance to unseating of the valve will be varied so asto control the vacuum to be effective in the respective duct or vacuum line.

In the diagrammatic illustration inF-igure lthe actuator piston 19 has just completed a movement to, the rightand has effected a shifting of the control valve plunger 29 to the position illustrated at the rightin said view against the action of the spring 35. It is to be noted that the air vent 37, 38 is out of effective cornmunication and the elbow. 39 isdisposedto open com munication between the vacuum ducts-42 and;43 into. the left hand end of theleft shift control-actuator. cylinder 4 E. Thus the parts are in a position to bring about a shifting of the actuator piston 19 to the left. Air at atmospheric pressure entering the vent 47 will force the piston 48 to the left and shift the valve plunger 11 to the left, imparting similar movement to the free piston 62 in the control actuator cylinder thereof. It will be noted that the piston heads 12 are so placed as to be effective when the piston is positioned at each limit of endwise movement thereof for connecting the intermediate vacuum port 7 with the vacuum and air port 16 or 1'7 at the particular end of the cylinder, and for isolating the particular vacuum and air port from. the adjacent air vent at said end, While connecting the vacuum and air port and the air vent at the other end of the cylinder and isolating them from said intermediate vacuum port 7. In the illustration in Figure l, the portion of the cylinder 18 to the right of the piston 19 has been evacuated, and. air at atmospheric pressure entering through the vent 17 and duct 25' has been effective against the piston in the: left hand end of said cylinder to force the same tov the right hand limit position shown in Fig-- ure 1. The reversing of the position of the valve plunger 11 as above described will bring about an evacuation of the left hand end, of the cylinder 18 through the duct 25 and the. intermediate port 7, and airat atmospheric pressure entering through the vent 15 and the duct 24 will be active. in the cylinder 18 to force the piston 19 to the left. During this time it is to be noted that the right shift control valve F is in a position for venting the right hand end of the right shift control actuator cylinder G through the vent 59 and communicating horizontal elbow passage in the valve plunger 52, the connecting duct 56 and the port 57. i

As, the. actuator piston 19 is moved to the left hand limit of its strolteit will shift the valve plunger 52 against the action of its opposing spring and bring the vertical elbow passage into position for openingcommunication between the vacuum duct 54 and the connecting duct 56 to evacuate the right hand end of the right shift control actuator cylinder 60 throughthe port 57. Air at atmospheric pressure now entering thecylinder 60 through the vent 61 willbe effective to force thepiston 62 to the right and bring about a shifting of the control valve plunger 11 to the position illustrated in Figure 1. This will bring about an evacuation of the right hand end of the actuator cylinder 18 through the duct 24 and intermediate port 6, and air at atmospheric pressure entering through the vent 15 connecting duct 25 will act upon the left hand end of the actuator piston 19 to force the same to the right, or to the position illustrated inFigure 1, thus completing the cycle. It is to be understood that so long. as the vacuum source is maintained in the line 6 at the value predetermined by adjustment of the valve 9; the reciprocation of the actuator piston 19 and its plungers 20'will continue in the manner described;

It has been explained that the severalair vents are adjustable, one of the valves. being shown in detail in Figure 5. This is an important feature because byv controlling these vents it is possible. to. control the rateof movement of the pistons under Whatever value of vacuum is being used. Also, by controlling the valve 9 the value of the vacuum to be effective in the .line 6 and the branches 42 and 54 can be controlled, and the control valves and 58 can be utilized to controlthe value of'the vacuum effective inthe connectingducts 43. and 56. In one, desirable example ofcontrol twenty inches of vacuumbas been maintainedinthe main. line.6 and, thebranclulines 42 and 54, functioning in combination with..-five. inches of vacuum in the connecting duct 56'and ten. inches'of vacuum in the connecting duct 43. In this manner it is possible to vary the speed of'the projection and retraction strokes of the-pistons 62 and 48'.

In theexample above referred to it is to. be noted that the five-inch and ten-inch'vacuum' controls are in .tlie intermediate connecting lines 56 and' 43" between' the control valve F and 'shifter-cylinderGWand-thewontrol valve D and the shifter cylinder 46 respectively. Because of the fact that the control valves F and D are opened momentarily to the main vacuum line 6 through the branches 54 and 52 respectively, the respective vacuum value controlling valves 58 and 45 can control the eifective pressure differentials in the respective right and left shift control actuator cylinders G and E in the manner desired without objectionable modification of the primary vacuum control in the main line in advance of the control valve 9 or between the individual valves 58, 45, 9 and the evacuating pump or suction source.

It will also be apparent that the venting adjustments can be utilized to vary the rate of movement of the piston 19 in either direction.

It will be apparent that the apparatus disclosed herein is very flexible in use and installation. The reciprocating motion of the piston 19 and its plungers can be transmitted directly or indirectly in the form of reciprocation to another connected part or mechanism, or this motion can be transmitted in other forms by connection with suitable movement transmitting agencies.

The fact that the movement imparted to the main or actuator piston 19 is imparted by air at atmospheric pressure, the selected power applying installations can be controlled or selected so that there need be no concern about breakage of parts moved by or actuated by movement of the piston 19.

It is important to note that the vacuum connection in 6, 42, 54 is always open, all venting being at the individual valves and not in the main vacuum line or said branches thereof. Adjustment of the effective vacuum at the several places mentioned makes it possible to control the apparatus so that the power applying or actuator piston may move rapidly in one direction, and slowly in the other, if desired, or rapidly both ways, or slowly both ways.

It is also to be understood that while in this example illustration provision is made for continuous reciprocation of the piston 19, by reason of the shifting of the valves F and D at the opposite piston stroke limits, it is to be understood that one of the valves D or F can be placed at a remote point and subject to actuation by a mechanical actuator or timer, or it can be engaged by material or articles being-fed so that as the article or material comes against the valve and shifts the same, it will bring about an operation of the piston to actuate some mechanism for working upon or shifting said material or article, and the moving piston will automatically actuate the other valve so as to bring about a return movement of the piston, ation thereof.

While one example arrangement of the invention is disclosed herein, it is to be understood that other arrangements and modification of parts may be made without departing from the spirit and scope of the invention as defined in the appended claims.

I claim:

1. In apparatus of the character described, a power cylinder having a single solid actuator piston reciprocable therein and an actuator plunger fixed on the piston and projecting from each end of the cylinder and subject to connection with a part to which motion is to be imparted, and a vacuum and air port at each end of the cylinder; a control cylinder separate and apart from said power cylinder and having a vacuum port intermediately of the ends thereof, a vacuum and air port and an air vent in adjacent longitudinally spaced relation at each end thereof, and a valve piston reciprocable therein and having a plunger projecting from each of its ends and through the adjacent ends of the control cylinder and heads on the piston within the cylinder and spaced to be eifective when the piston is positioned at each limit of endwise movement thereof for connecting the intermediate vacuum port with the vacuum and air port at the particular control cylinder end and for isolating the particular vacuum and air completing a single cycle operport from the adjacent air vent at said end while con necting the vacuum and air port and the air vent at the other control cylinder end and isolating them from said intermediate vacuum port; means connecting the intermediate vacuum port with a vacuum source; means connecting the vacuum and air ports at like ends of'the power and control cylinders; and independent means mounted externally of the control cylinder and at least in part controllable by movement of the actuator piston and shiftable into position for being engageable with each of the endwise projecting plungers of the valve piston for shifting the valve piston to control reciprocation of the actuator piston.

2. In apparatus of the character described, a power cylinder having a single solid actuator piston reciprocable therein and an actuator plunger fixed on the piston and projecting from each end of the cylinder and subject to connection with a part to which motion is to be imparted, and a'vacuum and air port at each end of the cylinder; a control cylinder separate and apart from said power cylinder and having a vacuum port intermediately of the ends thereof, a vacuum and air port and an air vent in adjacent longitudinally spaced relation at each end thereof, and a valve piston reciproca'ble therein and having a plunger projecting from each of its ends and through'the adjacent ends of the control cylinder and heads on the piston Within the cylinder and spaced to be effective when the piston is positioned at each limit of endwise move ment thereof for connecting the intermediate vacuum port with the vacuum and air port at the particular control cylinder end and for isolating the particular vacuum and air port from the adjacent air vent at said end while connecting the vacuum and air port and the air vent at the other control cylinder end and isolating them from said intermediate vacuum port; means connecting the intermediate vacuum port with a vacuum source; means connecting the vacuum and air ports at like ends of the power and control cylinders; and independent means mounted externally of the control cylinder and at least in part controllable by movement of the actuator piston and shiftable into position for being engageable with each of the endwise projecting plungers of the valve piston for shifting the valve piston to control reciprocation of the actuator piston, there also being included an adjustable vent plug in at least one of the air vents of the control cylinder for regulating the rate of travel of at least one stroke of the actuator piston.

3. In apparatus of the character described, a power cylinder having a single solid actuator piston reciprocable therein and an actuator plunger fixed on the piston and projecting from each end of the cylinder and subject to connection with a part to which motion is to be imparted, and a vacuum and air port at each end of the cylinder; a control cylinder separate and apart from said power cylinder and having a vacuum port intermediately of the ends thereof, a vacuum and air port and an air vent in adjacent longitudinally spaced relation at each end thereof, and a valve piston reciprocable therein and having a plunger projecting from each of its ends and through the adjacent ends of the control cylinder and heads on the piston within the cylinder and spaced to be effective when the piston is positioned at each limit of endwise movement thereof for connecting the intermediate vacuum port with the vacuum and air port at the particular control cylinder end and for isolating the particular vacuum and air port from the adjacent air vent at said end while connecting the vacuum and air port and the air vent at the other control cylinder "end and isolating them from said intermediate vacuum port; means connecting the intermediate vacuum port with a vacuum source; means connecting the vacuum and air ports at like ends of the power and control cylinders; and independent means mounted externally of the control cylinder and at least in part controllable by movement of the actuator piston and shiftable into position for being. engageahle with each of the endwise projectingplun-gers oi the valve piston for shifting the valve piston. to control reciprocation of the actuator piston, there also being included. an adjustable vent plug in the air vent at each end of the control cylinder for regulating the rate of travel of the actuator piston during. reciprocation thereof.

4. In. apparatus of the character described, a. power cylinder having an actuator piston reciprocable therein and an actuator plunger fixed on the piston and projecting. from each end of. the cylinder and. subject to connection with. a part to which motion is to be imparted, and a. vacuum and air port at each end of the cylinder; a control cylinder having a vacuum port intermediately of the ends. thereof, a vacuum and air port and an air vent in adjacent longitudinally spaced relation at each end thereof, and a valvepiston reciprocable therein and having a. plunger projecting from each of its ends and through the adjacent ends of the control cylinder and heads on. the piston within the cylinder and spaced to be effective when the piston is positioned at. each limit. ofi endwise movement thereof for connecting the inter mediate vacuum port with the vacuum: and air port at the. particular control cylinder end. and for isolating the. particular vacuum and air port from the adjacent air ventat said end While connecting the vacuum and air port and the air vent at the other control cylinder end and isolating them from said intermediate vacuu-mport; means connecting the intermediate vacuum port with a vacuum source; means connecting the vacuum. and air ports at like ends of the power and control cylinders; and independent means engageable with each of the endwise projecting plungers of the valve piston for shifting the valve piston to control reciprocation of the actuator piston, each said valve piston shifting means including a fluid pressure operable piston means for shifting the valve piston, and control. valve means operable by movement. ofthe actuator piston.

-1n. apparatus of the character described, a power cylinder having an actuator piston reciprocable therein and. an actuator plunger fixed on the piston and projecting. from. each end. of the cylinder and subject to connection with a part to which motion is to be imparted, and a: vacuum and air port at each end of the cylinder; a control cylinder having a vacuum port intermediately ofv the ends. thereof, a vacuum and air port and. an air vent in adjacent longitudinally spaced relation. at each end thereof, and a valve piston reciprocable therein. andhaving a plunger projecting from each of its ends and through the adjacent ends of the control cylinder and heads on the piston. Within. the cylinder and spaced to. be effective when the piston is positioned at each limit of endwise movement thereof for connecting the intermediate vacuum port with the vacuum and air port at the particular control cylinder end and for isolating the particular vacuum and air port from the. adjacent air vent. at said end. while connecting the vacuum and air port and the air vent at the other control cylinder end and isolating them from said intermediate vacuum port; means connecting the intermediate vacuum port with a vacuum source; means connecting the vacuum. and air ports at like ends of. the power and control cylinders; and independent means engageable with each of the endwise projecting plungers of the valve piston for shifting the valve piston to. control reciprocation of the actuator piston, said valve piston. shitting means including an individual fluid pressure operable piston. for shifting; the valve piston in each direction. of movement. thereof and an individual control. valve means operable by movement of the actuator piston.

6. In apparatus of the character described, a power cylinder having. an actuator piston reciprocable therein and. an actuator plunger fixed on the piston: andprojecting f-romeach end of the cylinder and subject. to connectiorrwith a part to which motion: is to beimparted, anda vacuum: and air port at each end. ofthe cylinder; a control. cylinder havinga vacuum portintermediately of the. ends thereof, a vacuum. and airport and an air ventisadjacent longitudinally spaced relation. at eachend thereof, and avalve piston reciprocable' therein and having. a. plunger. projecting from each of its ends and through the adjacent ends of the control cylinder and heads on the piston within the cylinder and spaced to be efliective when the piston is positioned at each limit of endwise movement 7 thereof for connecting the intermediate vacuum port with the vacuum and air port at the particular control cylinder end and for isolating the particular vacuum a-nd'air port from the adjacent air vent at said end while connecting the vacuum and air port and the air vent at the other control cylinder end and isolatingthem from said intermediate vacuum port; means connecting the intermediate vacuum port with a vacuum source; means connecting the vacuum and air ports at like ends'of the power and control cylinders; and independent means engageahle with each of the endwise projecting plungers of the valve piston for shifting the valve piston. to control reciprocation of the actuator piston, said valve piston shitting means-including an individual fluid pressure operable piston for shifting the valve piston. in each direction of movement thereof, an individual valve means for controlling the operation of each said fluid pressure operated piston, each said individual valve means being operable by the actuator piston at one limit of its reciprocation.

7. ln' apparatus of. the character described; a power cylinder having an actuator piston reciprocaole therein and an actuator plunger fixedon the piston andproj'ecting from each end of the cylin'der'and subject to connection with a part to which motion is' to be imparted, and a vacuum and air port at each end of the cylinder; a control cylinder having a vacuum port interniediately of the ends thereof, avacuum and air port and-an air'vent in adjacent longitudinally spaced relation at each end thereof, and a valve piston reciprocable therein and having a plunger projecting from each of its ends and through the adjacent ends of the-control cylinder and heads on" the piston within the cylinder and spaced to be efiective when the piston is positioned at each limit of endwise movement thereoffor connecting the intermediate vacuum port with the vacuum and air port atthe particular control cylinder end and for isolating theparticula-r vacuum and air port from the adjacent air vent at said end while connecting the vacuum and air port and the'air vent at the other control cylinder end and isolating them from said intermediate vacuum port; means connecting the intermediate vacuum port with a vacuum source; means connecting the vacuum and air ports atv like ends ofthe power and control cylinders; and independent means engageable with each of the endwise projecting plungers of the valve piston for shifting the valve piston to control reciprocation of the actuator piston, said valve piston shift-ingmeans' including an individual fluid pressure operable piston for shifting the valve piston in each direction of movement thereof, an individual valve means for controlling the operation of each said fluid pressure operated piston, at least one of saidindividual valve means being operable by the actuator piston at one limit of itsreciprocation.

8. In apparatus of the character described, a power cylinder having anactuator piston reciprocable therein and an: actuator plunger fixed on the piston and projecting. from each end: of the cylinder and subject to connectionwith a part to which motion is to beimparted', and a vacuum and airport at each end of the cylinder; a control cylinder having a vacuum port intermediately of the ends thereof, a vacuum. and airportand an air vent in adjacent longitudinally spaced relation ateach end thereof; and a valve piston reciprocable therein and. having a plunger projecting. from each of its. ends and through: the adjacent ends of the control cylinder and heads on the piston within the cylinder and spaced to be effective: when the piston is. positioned at each limit of endwise movement thereof for connecting: the intermediate vacuum port with the vacuum and air port at the particular control cylinder end and for isolating the particular vacuum and air port from the adjacent air vent at said end while connecting the vacuum and air port and the air vent at the other control cylinder end and isolating them from said intermediate vacuum port; means connecting the intermediate vacuum port with a vacuum source; means connecting the vacuum and air ports at like ends of the power and control cylinders; and independent means engageable with each of the endwise projecting plungers of the valve piston for shifting the valve piston to control reciprocation of the actuator piston, valve piston shifting means including a fluid pressure operable piston means for shifting the valve piston, and control valve means operable by movement of the actuator piston, said fluid pressure operable piston means being atmospheric air operated under vacuum control through the actuator piston actuated valve means.

9. In apparatus of the character described, a power cylinder having an actuator piston reciprocable therein and an actuator plunger fixed on the piston and projecting from each end of the cylinder and subject to connection with a part to which motion is to be imparted, and a vacuum and air port at each end of the cylinder; a control cylinder having a vacum port intermediately of the ends thereof, a vacuum and air port and an air vent in adjacent longitudinally spaced relation at each end thereof, and a valve piston reciprocable therein and having a plunger projecting from each of its ends and through the adjacent ends of the control cylinder and heads on the piston within the cylinder and spaced to be eifective when the piston is positioned at each limit of endwise movement thereof for connecting the intermediate vacuum port with the vacuum and air port at the particular control cylinder end and for isolating the particular vacuum and air port from the adjacent air vent at said end while connecting the vacuum and air port and the air vent at the other control cylinder end and isolating them from said intermediate vacuum port; means connecting the intermediate vacuum port with a vacuum source; means connecting the vacuum and air ports at like ends of the power and control cylinders; and independent means engageable with each of the endwise projecting plungers of the valve piston for shifting the valve piston to control reciprocation of the actuator piston, each valve piston shifting means including a fluid pressure operable piston means for shifting the valve piston, and control valve means operable by movement of the actuator piston, each said fluid pressure operable piston means being atmospheric air operated under vacuum control through the actuator piston actuated valve means and including means for varying the effective pressure of the atmospheric air.

10. In apparatus of the character described, a power cylinder having an actuator piston reciprocable therein and an actuator plunger fixed on the piston and projecting from each end of the cylinder and subject to connection with a part to which motion is to be imparted, and a vacuum and air port at each end of the cylinder; a control cylinder having a vacuum port intermediately of the ends thereof, a vacuum and air port and an air vent in adjacent longitudinally spaced relation at each end thereof, and a valve piston reciprocable therein and having a plunger projecting from each of its ends and through the adjacent ends of the control cylinder and heads on the piston within the cylinder and spaced to be effective when the piston is positioned at each limit of endwise movement thereof for connecting the intermediate vacuum port with the vacuum and air port at the particular control cylinder end and for isolating the particular vacuum and air port from the adjacent air vent at said end While connecting the vacuum and air port and the air vent at the other control cylinder end and isolating them from said intermediate vacuum port; means connecting the intermediate vacuum port with a vacuum source; means connecting the vacuum and air ports at like ends of the power and control cylinders; and independent means engageable with each of the endwise projecting plungers of the valve piston for shifting the valve piston to control reciprocation of the actuator piston, each valve piston shifting means including a fluid pressure operable piston means for shifting the valve piston, and control valve means operable by movement of the actuator piston, said fluid pressure operable piston means being atmospheric air operated under vacuum control through the actuator piston actuated valve means, and means being included for varying the effective value of the controlling vacuum.

11. In apparatus of the character described, a power cylinder having an actuator piston reciprocable therein and an actuator plunger projecting from each end thereof and subject to connection with a part to which motion is to be imparted, and a vacuum and air port at each end thereof; a control cylinder having a vacuum port intermediately of the ends thereof, a vacuum and air port and an air vent in adjacent longitudinally spaced relation at each end thereof, and a valve piston reciprocable therein and having plungers projecting from its ends through the ends of the control cylinder and heads on the piston within the cylinder and spaced to be effective when the piston is positioned at each limit of endwise movement theerof for connecting the intermediate vacuum port with the vacuum and air port at the particular control cylinder end and for isolating the particular vacuum and air port from the adjacent air vent at said end While connecting the vacuum and air port and the air vent at the other control cylinder end and isolating them from said intermediate vacuum port; means connecting the intermediate vacuum port with a vacuum source; means connecting the vacuum and air ports at like ends of'the power and control cylinders; and means for bringing about a shifting of the valve piston to control reciprocation of the actuator piston, said last named means including an individual fluid pressure operable piston for shifting the valve piston in each direction of movement thereof, an individual valve means for controlling the operation of each said fluid pressure operated piston, each said individual valve means including a casing and a spring projected plunger disposed to be engaged and returned to its retracted position by movement of the actuater piston to one limit of its reciprocation and said casing having a vacuum port, a vacuum and air port and an air port, and said plunger having provision for connecting the vacuum port and the vacuum and air port when projected and for connecting the vacuum and air port with the air port when retracted, and each said fluid pressure operable piston being movable in a cylinder having an air port at one end and a vacuum and air port at its opposite end and connected With the vacuum and air port of the controlling valve, and means connecting the vacuum port of each valve with the vacuum source.

12. in apparatus of the character described, a power cylinder having an actuator piston reciprocable therein and an actuator plunger projecting from each end thereof and subject to connection with a part to which motion is to be imparted, and a vacuum and air port at each end thereof; a control cylinder having a vacuum port intermediately of the ends thereof, a vacuum and air port and an air vent in adjacent longitudinally spaced relation at each end thereof, and a valve piston reciprocable therein and having plungers projecting from its ends through the ends of the control cylinder and heads on the piston within the cylinder and spaced to be effective when the piston is positioned at each limit of endwise movement thereof for connecting the intermediate vacuum port with the vacuum and air port at the particular control cylinder end and for isolating the particular vacuum and air port from the adjacent air vent at said end while connecting the vacuum and air port and the air vent at the other control cylinder end and isolating them from said intermediate vacuum port; means connecting the intermediate vacuum port with a vacuum source; means connecting the vacuum and air ports at like ends of the power and control cylintiers; and meansfor bringing about ashifting of the valve piston. to control reciprocation: of the actuator piston, said last named means including an individual fluid pressure operable piston for shifting the valve piston in each direction of movement. thereof, an individual. valve means for controlling the operation of each said fluid pressure opera-ted piston, eachsaid individual valve means including a casing anda spring projected plunger disposed to be engaged and returned toits retracted position by movement ot the actuator piston to one. limit of itsrcciproca tiona-ndsaidcasing having avacuum port, a vacuum and air port and an air port, and said plunger having provision for connecting the vacuum port and the vacuum and air port when projected and for connecting the vacuum and air port with the air port when. retracted, and each said fluid pressure operable piston being movable in a cylinder having an air port at one endand. a vacuum and air port at its opposite endand connectedwith thevacuum and air port of the controlling valve,.and means connecting the vacuum port of each valve with the vacuum source, means in the connection. between eachcontrol valve and the cylinder controlled thereby for varying the value of the vacuum. to be effective therein, and means in each air port for varying the freedom of ingress and egress of air.

13. In apparatus of the character described, a power cylinder having an actuator piston reciprocable therein and an actuator plunger projectingfrern each end thereof and subject to connection with apart to which motion is robe imparted, and; a vacuumv and air port at each end thereof; a control cylinder having a vacuum port intermediately of the ends thereof, aivacuum and air port and an air vent. inv adjacent longitudinally spaced relation at each end thereof, andza. valve piston reciprocable therein and having;plungers-projecting'fromits-ends through the ends of the control cylinderandt heads on the piston within the cylinder and spacedto-be effective When the piston is positioned at each limit of endwisemovement thereof for connecting the intermediate vacuumport with the vacuum and air port at. the particular control cylinder end and for isolating the particular vacuum and air port from the adjacent air vent. at saidend while connecting the vacuum and air port and the air vent at the other control cylinder end. and isolating them from said intermediate vacuum port; means connecting the intermediate vacuum port with a vacuum source; means connecting the vacuum and air ports at like ends of the power and control. cylinders; and means for. bringing about a shifting of the valve piston to control reciprocation of the actuator piston, said last named means including an individual fluid pressure operable piston for shifting. the valve piston in each direction of movement thereof, an individual valve means for controlling theoperation of each said fluid pres sure operated piston, each said individual valve means ineluding a casing and a spring projected plunger and said casing having avacuurrr port, a vacuum and air port and an air port, and said plunger having provision for connecting the vacuum port and the vacuum and air port when projected and for connecting the vacuum and air port with the air port when retracted, and each said fluid pressure operable piston being movable in a cylinder having an air port at one end and a vacuum and air port at its opposite end and connected: with the vacuum and air port of the controlling valve, and means connecting the vacuum port of each valve with the vacuum source, at least one said individual valve means being positioned to have its spring projected plunger engaged and returned to its retracted! position: by movement of the actuator piston to one limit of its reciprocation.

References Cited in the file of this patent UNITED STATES PATENTS (Addition to No. 530,760) 

